roadrunner.hdmap.Junction

R2026b

Define junction in RoadRunner HD Map

Since R2022b

Description

A roadrunner.hdmap.Junction object enables you to define a junction in a RoadRunner HD Map scene model. A Junction represents a logical grouping of a set of lanes, typically involving a crossing (or convergence or divergence) between multiple roadways. Use this object to define the geometry and connectivity of lanes at a crossing between multiple roadways. To learn how to create a complete T-junction with roads, maneuver lanes, and traffic signal phases that include bulb-level signal control, see Build Signalized Junction Using RoadRunner HD Map.

Creation

Syntax

junction = roadrunner.hdmap.Junction

junction = roadrunner.hdmap.Junction(PropertyName=Value)

Description

junction = roadrunner.hdmap.Junction creates an empty lane junction.

junction = roadrunner.hdmap.Junction(PropertyName=Value) specifies one or more properties of the junction using name-value arguments. For example, ID="Junction1" specifies the ID of the junction as "Junction1".

Properties

ID — ID of junction

"" (default) | character vector | string scalar

ID of the junction, specified as a character vector or string scalar.

Example: rrMap.Junctions= roadrunner.hdmap.Junction(ID="Junction1") creates a junction with id Junction1 in a RoadRunner HD Map.

Data Types: char | string

Geometry — Geometry of junction object

roadrunner.hdmap.MultiPolygon.empty (default) | roadrunner.hdmap.MultiPolygon object

Geometry of the junction object, specified as a roadrunner.hdmap.MultiPolygon object. The geometry of the junction object is represented by a set of non-overlapping polygons. Each polygon consists of an outer boundary and can optionally contain one or more interior regions (holes). While polygons cannot overlap, you can define a polygon within a hole in another polygon. When a junction requires multiple polygons, you must group the polygons inside a single roadrunner.hdmap.MultiPolygon object.

Lanes — IDs of connecting lanes

roadrunner.hdmap.Reference.empty (default) | array of roadrunner.hdmap.Reference objects

IDs of connecting lanes, specified as an array of roadrunner.hdmap.Reference objects. These lanes can connect topologically to other lanes enclosed in the junction. For example, a small roundabout (mini-circle) might consist of a single junction whose enclosed lanes include a ring formation.

Configurations — Configurations of traffic signal phases at junction

roadrunner.hdmap.JunctionConfiguration.empty (default) | array of roadrunner.hdmap.JunctionConfiguration objects

Since R2025a

Configurations of traffic signal phases at the junction, specified as an array of roadrunner.hdmap.JunctionConfiguration objects. Specifying multiple configurations enables a junction to have various phase presets, such as all signals blinking red or a split phase setup. Simulators can dynamically switch or select between these presets.

Examples

Add Junction to RoadRunner HD Map

Create an empty RoadRunner HD Map.

rrMap = roadrunnerHDMap

rrMap = 
  roadrunnerHDMap with properties:

                 Author: ""
           GeoReference: [0 0]
     GeographicBoundary: []
                  Lanes: [0×1 roadrunner.hdmap.Lane]
            SpeedLimits: [0×1 roadrunner.hdmap.SpeedLimit]
         LaneBoundaries: [0×1 roadrunner.hdmap.LaneBoundary]
             LaneGroups: [0×1 roadrunner.hdmap.LaneGroup]
           LaneMarkings: [0×1 roadrunner.hdmap.LaneMarking]
              Junctions: [0×1 roadrunner.hdmap.Junction]
           BarrierTypes: [0×1 roadrunner.hdmap.BarrierType]
               Barriers: [0×1 roadrunner.hdmap.Barrier]
              SignTypes: [0×1 roadrunner.hdmap.SignType]
                  Signs: [0×1 roadrunner.hdmap.Sign]
      StaticObjectTypes: [0×1 roadrunner.hdmap.StaticObjectType]
          StaticObjects: [0×1 roadrunner.hdmap.StaticObject]
    StencilMarkingTypes: [0×1 roadrunner.hdmap.StencilMarkingType]
        StencilMarkings: [0×1 roadrunner.hdmap.StencilMarking]
      CurveMarkingTypes: [0×1 roadrunner.hdmap.CurveMarkingType]
          CurveMarkings: [0×1 roadrunner.hdmap.CurveMarking]
            SignalTypes: [0×1 roadrunner.hdmap.SignalType]
                Signals: [0×1 roadrunner.hdmap.Signal]

Create a road lane marking using a roadrunner.hdmap.Junction object. Specify the junction ID.

rrMap.Junctions = roadrunner.hdmap.Junction(ID="Junction1")

rrMap = 
  roadrunnerHDMap with properties:

                 Author: ""
           GeoReference: [0 0]
     GeographicBoundary: []
                  Lanes: [0×1 roadrunner.hdmap.Lane]
            SpeedLimits: [0×1 roadrunner.hdmap.SpeedLimit]
         LaneBoundaries: [0×1 roadrunner.hdmap.LaneBoundary]
             LaneGroups: [0×1 roadrunner.hdmap.LaneGroup]
           LaneMarkings: [0×1 roadrunner.hdmap.LaneMarking]
              Junctions: [1×1 roadrunner.hdmap.Junction]
           BarrierTypes: [0×1 roadrunner.hdmap.BarrierType]
               Barriers: [0×1 roadrunner.hdmap.Barrier]
              SignTypes: [0×1 roadrunner.hdmap.SignType]
                  Signs: [0×1 roadrunner.hdmap.Sign]
      StaticObjectTypes: [0×1 roadrunner.hdmap.StaticObjectType]
          StaticObjects: [0×1 roadrunner.hdmap.StaticObject]
    StencilMarkingTypes: [0×1 roadrunner.hdmap.StencilMarkingType]
        StencilMarkings: [0×1 roadrunner.hdmap.StencilMarking]
      CurveMarkingTypes: [0×1 roadrunner.hdmap.CurveMarkingType]
          CurveMarkings: [0×1 roadrunner.hdmap.CurveMarking]
            SignalTypes: [0×1 roadrunner.hdmap.SignalType]
                Signals: [0×1 roadrunner.hdmap.Signal]

Limitations

• Although you can define traffic control logic using roadrunner.hdmap.JunctionConfiguration, roadrunner.hdmap.Phase, and roadrunner.hdmap.JunctionLaneState objects, and export it to an HD map file, RoadRunner does not visualize or apply this information when you import the map.

Version History

Introduced in R2022b

R2025a: Configure traffic signal phases at junction

The roadrunner.hdmap.Junction object now has the Configurations property, which enables you to configure traffic signal phases at junctions in a RoadRunner HD Map scene model.